This invention relates generally to thermocouple and more particularly to a thermocouple assembly and a method of making it which facilitates secure and accurate location during use.
In many applications such as injection molding it is necessary to measure the temperature of a metal body at a specific location. In the past it has been known to provide a ring clip attached to the insulated wires which could be screwed at a particular location to the body. While this is satisfactory for many applications, it has been found in some high temperature situations where gases create a corrosive environment that the hermetically sealed wires must be protected against breakage so that the thin iron wire is safe from corrosion.
More recently, in order to overcome these problems, thermocouples have been provided with an integral thin stainless steel sheath as shown in the Temco Electric Heater Corporation brochure entitled "Thermocouples for Integrated Heating Torpedoes". While this overcomes the corrosion and degredation problems, the elongated sheath must of necessity have a small diameter so it is flexible to fit in different positions for different applications. However secure and accurate location of the forward end of the protective sheath containing the thermocouple remains a problem. As the stainless steel sheath must be small and thin to be flexible, it does not have sufficient strength to withstand clamping. It works well if it can be inserted into a small diameter bore in the body, but this is not always practicable.